Text entry is one of the crucial issues for third generation cellular phones as well as for other compact hand held wireless communication devices.
Many methods have been suggested in recent years. Among the most popular ones are methods that reduce the number of keys by grouping several letters together on the same key and use a prediction or disambiguating system to generate the desired text. Since fewer keys are needed, smaller keypad size or larger key size is obtainable. Less finger movements are needed hence typing speed is potentially increased. However, if the user desires to write a word that is not in the device's dictionary database, or if more than one valid word exists for a sequence of letter entries, a considerable degradation in typing speed and comfort occurs.
In U.S. Pat. No. 5,818,437 entitled “reduced keyboard disambiguating computer”, Grover, et al., a 3 by 4 numeric keypad is presented where each key is associated with 3 or 4 letters. In U.S. Pat. No. 5,847,697 entitled “Single-handed keyboard having keys with multiple characters and character ambiguity resolution logic”, Sugimoto, a half size QWERTY keyboard, with two letters associated to most of the keys, is presented. Much more prior art exists for similar arrangements, as well as various implementations of text prediction or disambiguation processing.
Several ways to present the words list to the user as well as receiving the user selection of the desired word, including word a completion feature, are also available in prior art.
None of the prior art combines the predictive text method together with simple single letter text entry into one unified text entry system.
The current invention offers a way of combining predictive text with a simple single letter text entry using several arrangements such as multi-functional keys to form a family of new text entry systems that takes the best features from both methods.